The Synology D4RD-2666 series offers DDR4 RDIMM ECC memory modules in 16GB and 32GB capacities, specifically designed for enterprise Synology NAS systems including the FlashStation FS3410, HD6500, and SA6400. These registered (buffered) ECC memory modules feature a 288-pin RDIMM form factor operating at 1.2V, providing reliable error-correcting code functionality to detect and correct data corruption in real-time for mission-critical environments. As official Synology memory upgrades, these modules undergo rigorous compatibility testing to ensure seamless integration with DiskStation Manager (DSM) and optimal performance in demanding workloads including virtualization, high-availability clustering, large-scale storage deployments, and 24/7 enterprise operations. The registered ECC design delivers enhanced data integrity, system stability, and scalability for business-critical applications, enabling faster start-up times, improved application responsiveness, and superior multitasking capabilities. Perfect for expanding memory capacity up to 1TB in the SA6400 or maximizing performance in enterprise NAS configurations, backed by Synology's quality assurance and reliability standards.